<template>
  <div class="upload-file">
    <el-upload
      ref="upload"
      :action="uploadFileUrl"
      :before-upload="handleBeforeUpload"
      :file-list="fileList"
      :on-error="handleUploadError"
      :on-exceed="handleExceed"
      :on-success="handleUploadSuccess"
      :show-file-list="false"
      :headers="headers"
      class="upload-file-uploader"
    >
      <!-- 上传按钮 -->
      <el-button size="mini" type="primary">
        选取文件
      </el-button>
      <!-- 上传提示 -->
      <template v-if="showTip" #tip class="el-upload__tip">
        请上传
        <template v-if="fileSize">
          大小不超过 <b style="color: #f56c6c">{{ fileSize }}MB</b>
        </template>
        <template v-if="fileType.length">
          格式为 <b style="color: #f56c6c">{{ fileType.join("/") }}</b>
        </template>
        的文件
      </template>
    </el-upload>

    <!-- 文件列表 -->
    <div class="upload-file-list el-upload-list el-upload-list--text" name="el-fade-in-linear" tag="ul">
      <div v-for="(file, index) in fileList" :key="file.id" class="el-upload-list__item ele-upload-list__item-content">
        <el-link :href="file.fileUrl" :underline="false" target="_blank">
          <span class="el-icon-document"> {{ file.fileName }} </span>
        </el-link>
        <div v-show="isDel" class="ele-upload-list__item-content-action">
          <el-link :underline="false" type="danger" @click="handleDelete(file, index)">
            删除
          </el-link>
        </div>
      </div>
    </div>
  </div>
</template>

<script>

export default {
  props: {
    // 值
    // eslint-disable-next-line vue/require-default-prop
    value: Array,
    isDel: {
      type: Boolean,
      default: true
    },
    // 大小限制(MB)
    fileSize: {
      type: Number,
      default: 20
    },
    // 文件类型, 例如['png', 'jpg', 'jpeg']
    fileType: {
      type: Array,
      default: () => ['doc', 'xls', 'ppt', 'txt', 'pdf']
    },
    // 是否显示提示
    isShowTip: {
      type: Boolean,
      default: true
    }
  },
  emits: ['input'],
  data () {
    return {
      uploadFileUrl: sessionStorage.getItem('APP_API1') + '/file/upload', // 上传的图片服务器地址
      headers: {
        Authorization: 'Bearer ' + this.$store.getters.token,
        grandType: '02'
      },
      fileList: []
    }
  },
  computed: {
    // 是否显示提示
    showTip () {
      return this.isShowTip && (this.fileType || this.fileSize)
    }
  },
  watch: {
    value: function (newVal) {
      this.fileList = this.value
    }
  },
  created () {
    this.fileList = this.value
  },
  methods: {
    // 上传前校检格式和大小
    handleBeforeUpload (file) {
      // 校检文件类型
      if (this.fileType && this.fileType.length !== 0) {
        let fileExtension = ''
        if (file.name.lastIndexOf('.') > -1) {
          fileExtension = file.name.slice(file.name.lastIndexOf('.') + 1)
        }
        const isTypeOk = this.fileType.some(type => {
          if (file.type.indexOf(type) > -1) return true
          if (fileExtension && fileExtension.indexOf(type) > -1) return true
          return false
        })
        if (!isTypeOk) {
          this.$message.error(`文件格式不正确, 请上传${this.fileType.join('/')}格式文件!`)
          return false
        }
      }
      // 校检文件大小
      if (this.fileSize) {
        const isLt = file.size / 1024 / 1024 < this.fileSize
        if (!isLt) {
          this.$message.error(`上传文件大小不能超过 ${this.fileSize} MB!`)
          return false
        }
      }
      return true
    },
    // 文件个数超出
    handleExceed () {
      this.$message.error('只允许上传单个文件')
    },
    // 上传失败
    handleUploadError () {
      this.$message.error('上传失败, 请重试')
    },
    // 上传成功回调
    handleUploadSuccess (res, file) {
      this.$message.success('上传成功')
      this.fileList.push({
        name: res.data.name,
        url: res.data.url,
        fileName: res.data.name,
        fileUrl: res.data.url
      })
      this.$emit('input', this.fileList)
    },
    // 删除文件
    handleDelete (file, index) {
      this.$confirm('是否确认删除文件名为"' + file.fileName + '"的数据项?', '警告', {
        confirmButtonText: '确定',
        cancelButtonText: '取消',
        type: 'warning'
      }).then(() => {
        this.fileList.splice(index, 1)
        this.$emit('input', this.fileList)
      }).then(() => {
        this.msgSuccess('删除成功')
      })
    },
    // 获取文件名称
    getFileName (name) {
      if (name.lastIndexOf('/') > -1) {
        return name.slice(name.lastIndexOf('/') + 1).toLowerCase()
      } else {
        return ''
      }
    }
  }
}
</script>

<style scoped lang="scss">
.upload-file-uploader {
  margin-bottom: 5px;
}
.upload-file-list .el-upload-list__item {
  border: 1px solid #e4e7ed;
  line-height: 2;
  margin-bottom: 10px;
  position: relative;
}
.upload-file-list .ele-upload-list__item-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: inherit;
}
.ele-upload-list__item-content-action .el-link {
  margin-right: 10px;
}
</style>
